To test your hiking kit/boots to see if it is all comfortable/fits you can do a day walk but carrying your full rucksack and kit (or stuff of similar weight). This will give you a idea of how your kit fits and the difference in hiking with a full rucksack compared to a daysack to help you judge how far you should aim for.
Most of your camping kit can be ...

Most gear you can test out in your house. Take your boots out on any trail, each time you go out pack a little bit more in your pack and get used to the weight. Come up with a good clothing layer system.
Make sure you can get your tent set up quickly. There is nothing like setting up in a downpour minutes before sundown. You can practice this inside.
Make ...

If you don't have a scale, you can still figure out roughly how much fuel is in each canister with a simple bowl of water. Drop a full canister in bowl of water and mark the water line. Then, drop an empty one in the bowl of water and mark the water line. This gives you your full and empty lines for reference.
Now you can drop each of your partially-full ...

All the other answers are correct and good.
Car-Camping
If the problem is that you want a realistic test but either (a) do not have much time, or (b) wisely do not want to go out backpacking on a test trip alone, then do a car camping trip as a "dress rehearsal".
Find a car-camping site.Preferably in the wild or woods, rather than a developed KOA-stlye ...

Looking at the photo, if the ground is as soft as that, burying the canister by 2-3 cm could help a lot. If you're camping at a beach and bury it halfway in the sand, then that should even work in high winds.
Apart from that, if you're willing to buy a new stove, there are a number of them that come with built-in legs, such as this one

I would imagine the "testing" others referred to is suitability for purpose rather than will the gear end up damaged or broken. For example, if using a new tent, have you practiced pitching it at home first rather than waiting until you have to use it while in the middle of nowhere? Or is the stove and cooking equipment you plan to carry able to cope with ...

If it seems unstable as in wobbly then you might get better results by clearing out the ground you place it on so you have a level surface to work with (or by building a level surface with rocks or what you can find)
Another option is to get legs that attach to the underside of the bottle to make the setup more stable. Here is an example from ebay, but ...

In my experience Coleman Fuel burns the cleanest out of everything that I've tried, it is unfortunately the most expensive and hard to find (relative to gasoline or diesel).
Unleaded - Cheap and widely available, burns well but a little sooty.
Diesel - Slightly less cheap (in UK/Europe) works very well. Use with wider jet. More sooty than unleaded.
I also ...

Kerosene, white gas (Coleman fuel) and unleaded should all work.
However you need to change the nozzle/jet where the fuel comes out depending on the fuel used.
I believe (though I'm not entirely sure) there are different diameter holes for different fuels - presumably due to different viscosity.
This MSR FAQ has some useful information, particularly the ...

As seen in the photos of the repair kits below, the wick is the fabric-like material which is made of fiberglass. It doesn't burn but does eventually degrade when exposed to the high heat of a stove.
A simple replacement wick could potentially be fashioned out of nearly any fiberglass insulation such as that used in home construction. Furnace filters are ...

The priming wick on multi-fuel stoves is usually made of fiberglass material, and provides more surface area which makes harder to light fuels easier to ignite.
Multi-fuel stoves (such as the one you mention, or the Whisperlight International) are able to burn a wide range of fuels -- some of which are not very volatile. For example, diesel fuel, and ...

When packing/carrying the stove there are two main aims: to not break it and not get the rest of your kit covered in fuel. There are some tips for achieving this:
pack the stove somewhere secure where it won't get too knocked about/crushed/bent. Most stoves will pack inside a pot/pan which is my preferred way of doing this.
Similarly for the fuel bottle ...

There can't be any general rule on testing equipment but you should have tested at least all the features that you think you will need during your journey. You also do not necessarily have to test all your stuff at once.
For "technical" equipment such as tents, stoves and the like, it might be enough to just learn their handling. Nothing is more annoying ...

Most things I can think of would stop it working even when full.
My one suggestion is, is the pump below the fuel line when on its side?
The fuel line is the white tube in the picture. If it is in the middle of the bottle and the fuel is low it might not be submerged when the bottle is horizontal. Have you tried putting the bottle vertically or rotating ...

I have successfully used mixtures of gasoline, diesel and kerosine in various portions and had no problems that couldn't be solved by swapping to the other jet. Use the suck it and see approach works fine without getting technical.
If availability is an issue and it comes to hot dinner or raw dinner are you really going to be that picky which fuel you use, ...

One expensive component is the cooking pot; depending on if you already have one, you might want to find a stove that is compatible with your existing pot.
Trail Designs have several models that can burn both alcohol and wood. You can order their stoves for specific pot sizes. I have experience with their Sidewinder Ti-Tri which can also burn esbit. I would ...

You should define whether you are asking about white gas stoves or isobutain (canister) stoves.
For most backpackers, your main decision will be between the 2 broad stove categories: canister fuel vs. liquid fuel. You may also want to consider one of the growing number of alternative-fuel options now available..
A good resource to get started if you ...

You can test everything at home, in your yard, and at the gym.
At home, test your water filter, setting up the tent in the backyard, assembling and lighting your stove and boiling some water (don't forget your windscreen), any fishing gear you might have, and setting up a fire in your backyard.
At the gym, take your loaded backpack with you and do some ...

You can get a hose or pipe which allows you to connect the burner to the hose then the hose to the canister. This allows you to put the burner closer to the ground, in a small divot, behind a stump or otherwise shielded from the wind.

Another two cents (experience: two Philmont expeditions). Do all you can at home to test things.
Boots: if you've got a pack, test the boots and break them in with local hikes. This also lets you work out the 'fit' of the pack -- find that sweet spot where the hip belt takes the weight and the shoulders stabilize. Gradually add weight to the pack up to ...

Try at forestry supply stores. The guys that sell pulaskis, fire pumps, etc. They have the entire setup for portable kitchens.
The ones I've seen were a separate stove and bottle, but the stove and pedestal were sized that the stove would stack on the bottle.
We used such a rig on a large canoe expedition, and used a pot that would fit the bottle and ...